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I~IOWNUmerics wave tank is a ~ tOOl by which variouS nonlinear wave - ac interactionpwhleln can be treated in time domain. As the face stage, we f~ our efforts on the devious of an effita saution tee~ of fully nofor waves. aam numtried of water - wavesconnected PwhlemS, es~ in a wave tank, is alwayS comas Of PartS: wave generation, P~ and a~. The effi~ Of a nUm~ wave tankdepends not Only on the qwhty Of the wave abotion tecboaue, which allowS the lOng times~ and keePS finite tank leng… 相似文献
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This study deals with the general numerical model to simulate the two-dimensional tidal flow, flooding wave (long wave) and shallow water waves (short wave). The foundational model is based on nonlinear Boussinesq equations. Numerical method for modelling the short waves is investigated in detail. The forces, such as Coriolis forces, wind stress, atmosphere and bottom friction, are considered. A two-dimensional implicit difference scheme of Boussinesq equations is proposed. The low-reflection outflow open boundary is suggested. By means of this model,both velocity fields of circulation current in a channel with step expansion and the wave diffraction behind a semi-infinite breakwater are computed, and the results are satisfactory. 相似文献
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The temporal and spatial evolutions of nonlinear wave group with an initial Gaussian envelope are theoretically studied under the governing of MNLS equations, demonstrating that the temporal and spatial versions of numerical model are not always consistent in the whole evolution process, particularly in the presence of strong nonlinearity. Moreover, a large set of numerical simulations, performed respectively by these two versions of numerical model, are systematically compared to mechanically generated waves with different initial directional spreading and Benjamin–Feir Index, mainly focusing on the evolution properties of surface elevations such as the coefficients of skewness and kurtosis, the probability density function, and the maximal surface elevation. On the whole, it can be argued that the statistical properties of both numerically simulated wave fields are basically consistent with the laboratory observations. 相似文献
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This study investigates the initialization of nonlinear free-surface simulations in a numerical wave flume.Due to the mismatch between the linear input wavemaker motion and the kinematics of fully nonlinear waves,direct numerical simulations of progressive waves,generated by a sinusoidally moving wavemaker,are prone to suffering from high-frequency wave instability unless the flow is given sufficient time to adjust.A time ramp is superimposed on the wavemaker motion at the start that allows nonlinear free-surface simulations to be initialized with linear input.The duration of the ramp is adjusted to test its efficiency for short waves and long waves.Numerical results show that the time ramp scheme is effiective to stabilize the wave instability at the start of the simulation in a wave flume. 相似文献
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The particle trajectory on a weakly nonlinear progressive surface wave obliquely interacting with a uniform current is studied by using an EulerLagrange transformation. The thirdorder asymptotic solution is a periodic bounded function of Lagrangian labels and time, which imply that the entire solution is uniformlyvalid. The explicit parametric solution highlights the trajectory of a water particle and mass transport associated with a particle displacement can now be obtained directly in Lagrangian form. The angular frequency and Lagrangian mean level of the particle motion in Lagrangian form differ from those of the Eulerian. The variations in the water particle orbits resulting from the oblique interaction with a steady uniform current of different magnitudes are also investigated. 相似文献
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Choi Young-Kwang Seo Seung-Nam Choi Jin-Yong Shi Fengyan Park Kwang-Soon 《海洋学报(英文版)》2019,38(7):36-47
A wave forecasting system using FUNWAVE-TVD which is based on the fully nonlinear Boussinesq equations by Chen(2006) was developed to provide an accurate wave prediction in the Port of Busan, South Korea. This system is linked to the Korea Operational Oceanographic System(KOOS) developed by Park et al.(2015). The computational domain covers a region of 9.6 km×7.0 km with a grid size of 2 m in both directions, which is sufficient to resolve short waves and dominant sea states. The total number of grid points exceeds 16 millions,making the model computational expensive. To provide real-time forecasting, an interpolation method, which is based on pre-calculated results of FUNWAVE-TVD and SWAN forecasting results at the FUNWAVE-TVD offshore boundary, was used. A total of 45 cases were pre-calculated, which took 71 days on 924 computational cores of a Linux cluster system. Wind wave generation and propagation from the deep water were computed using the SWAN in KOOS. SWAN results provided a boundary condition for the FUNWAVE-TVD forecasting system. To verify the model, wave observations were conducted at three locations inside the port in a time period of more than 7 months. A model/model comparison between FUNWAVE-TVD and SWAN was also carried out. It is found that, FUNWAVE-TVD improves the forecasting results significantly compared to SWAN which underestimates wave heights in sheltered areas due to incorrect physical mechanism of wave diffraction, as well as large wave heights caused by wave reflections inside the port. 相似文献
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Quanan Zheng Chang-Kuo Tai Jianyu Hu Hongyang Lin Rong-Hua Zhang Feng-Chun Su Xiaofeng Yang 《Journal of Oceanography》2011,67(4):365-376
Satellite altimeter sea level data from 1993 to 2008 are used to analyze the interaction of nonlinear Rossby eddies with the
Kuroshio at the Luzon Strait (LS). The sea level anomaly data show that the west Pacific (WP) is a source of nonlinear Rossby
eddies, and the South China Sea (SCS) is a sink. The LS serves as a gateway between the two. The scale analysis indicates
that eddies with a radius larger than 150 km are strong enough to significantly alter the Kuroshio and are able to modify
the local circulation pattern. Statistical analysis indicates that the probability for eddies to penetrate through the Kuroshio
may reach at least 60%. A case study of an anticyclonic mesoscale eddy passing through the LS in June–July 2004 indicates
that the Kuroshio behaves as an unsteady flow with its stream path frequently modified, in a way of cutting off, meandering
and branching during its interaction with the eddy. We therefore suggest that nonlinear Rossby eddies may play a significant
role in modification of the local circulation system near the LS and in exchanges of the mass, momentum and energy between
the WP and the SCS. 相似文献
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In the present paper, by introducing the effective wave elevation, we transform the extended ellip- tic mild-slope equation with bottom friction, wave breaking and steep or rapidly varying bottom topography to the simplest time-dependent hyperbolic equation. Based on this equation and the empirical nonlinear amplitude dispersion relation proposed by Li et al. (2003), the numerical scheme is established. Error analysis by Taylor expansion method shows that the numerical stability of the present model succeeds the merits in Song et al. (2007)’s model because of the introduced dissipation terms. For the purpose of verifying its performance on wave nonlinearity, rapidly vary- ing topography and wave breaking, the present model is applied to study: (1) wave refraction and diffraction over a submerged elliptic shoal on a slope (Berkhoff et al., 1982); (2) Bragg reflection of monochromatic waves from the sinusoidal ripples (Davies and Heathershaw, 1985); (3) wave transformation near a shore attached breakwater (Watanabe and Maruyama, 1986). Comparisons of the numerical solutions with the experimental or theoretical ones or with those of other models (REF/DIF model and FUNWAVE model) show good results, which indicate that the present model is capable of giving favorably predictions of wave refraction, diffraction, reflection, shoaling, bottom friction, breaking energy dissipation and weak nonlinearity in the near shore zone. 相似文献
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Probability distribution of surface slope for nonlinear random sea waves and calculation of whitecap
《海洋学报(英文版)》1997,(2)
Ｂａｓｅｄｏｎｔｈｅｎｏｎｌｉｎｅａｒｍｏｄｅｌｏｆｔｗｏ－ｄｉｍｅｎｓｉｏｎａｌｒａｎｄｏｍｓｅａｗａｖｅｓ，ａｓｔａｔｉａｔｉｃａｌｄｉｓｔｒｉｂｕｔｔｔ崳铮睿铮妫鳎幔觯澹螅酰颍妫幔悖澹螅欤铮穑澹澹幔悖簦簦铮簦瑁澹簦瑁椋颍洌铮颍洌澹颍椋螅洌澹颍椋觯澹洌猓酰螅椋睿纾簦瑁澹澹穑幔睿螅椋铮睿铮妫簦瑁澹悖瑁幔颍幔悖簦澹睿螅簦簦椋悖妫酰睿悖簦簦铮睿幔睿洌洌椋颍澹悖簦悖幔欤悖酰欤幔簦椋铮睿螅铮妫澹幔悖瑁铮颍洌澹颍恚铮恚澹睿簦拢幔螅澹洌铮睿簦瑁澹洌椋螅簦颍椋猓酰簦椋铮睿铮妫鳎幔觯澹螅酰颍妫幔悖澹螅欤铮穑澹洌澹颍椋觯澹洌椋睿簦瑁椋螅穑幔穑澹颍幔鳎瑁椋簦澹悖幔穑悖铮觯澹颍幔纾澹恚铮洌澹欤椋螅穑颍铮穑铮螅澹洌猓酰螅椋睿纾簦瑁澹欤椋恚椋簦螅酰颍妫幔悖澹螅欤铮穑澹幔螅幔悖悖椋簦澹颍椋铮睿铮妫鳎幔觯澹猓颍澹幔耄椋睿纾裕瑁澹鳎瑁椋簦澹悖幔穑悖铮觯澹恚纾澹澹穑颍澹螅螅澹洌猓觯簦瑁澹恚铮洌澹欤洌澹穑澹睿螅铮睿簦瑁颍澹澹穑幔颍幔恚澹簦澹颍螅鳎瑁椋悖瑁悖幔睿猓澹洌澹簦澹颍恚椋睿澹洌椋睿穑颍椋睿悖椋穑欤澹猓簦瑁澹欤椋睿澹幔颍鳎幔觯澹螅穑澹悖簦颍酰恚幔睿洌簦瑁颍澹澹耄椋睿洌螅铮妫鳎幔觯澹鳎幔觯澹椋睿簦澹颍幔悖簦椋铮睿 相似文献
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Ｆｕｌｌ－ｒａｎｇｅｎｏｎｌｉｎｅａｒａｎａｌｙｓｉｓｏｆｆａｔｉｇｕｅｂｅｈａｖｉｏｒｓｏｆｒｅｉｎｆｏｒｃｅｄｃｏｎｃｒｅｔｅｓｔｒｕｃｔｕｒｅｓｂｙｆｉｎｉｔｅｅｌｅｍｅｎｔｍｅｔｈｏｄ￥ＳｏｎｇＹｕｐｕ；ＺｈａｏＳｈｕｎｂｏ；ＷａｎｇＲｕｉｍ... 相似文献
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To investigate the nonlinear properties of wind waves, experiments are carried out in a wind-wave flume with slope bottom at different wind speeds and fetches. Both the internal structure and apparent features of the nonlin-earity of wind waves are studied by using bispectral and statistical analysis of surface elevations. The relations between bispectra and nonlinear apparent characteristics of wind waves are established and confirmed. 相似文献
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MO Jiaqi * WANG Hui LIN Wantao LIN Yihua. Anhui Normal University Wuhu China. Division of Computional Science E-Institute of Shanghai Universities Shanghai Jiaotong University Shanghai China. Chinese Academy of Meteorological Sciences Beijing China. State Laboratory of Numerical Modeling for Atmospheric Sciences Geophysical Fluid Dynamics Institute of Atmosheric Physics Chinese Academy of Sciences Beijing China 《海洋学报(英文版)》2005,(5)
1 IntroductionThe El Ni’o atmospheric physics oscillation is anabnormal phenomenon involved in the tropical Pacificocean- atmosphere interactions. Studies on the El Ni(ophenomenon are very attractive (Lin et al., 2000; Linet al., 2001, 2002; Wang, 2001; Feng et al., 2001;Feng et al., 2002; Liu et al., 2002; Wei and Chen,2003; Xie et al., 2002; Zhu et al., 2002; Pu et al.,2003; Gu et al., 2004; Yu and Liu, 2004). Lin and Mo(2004), Mo and Lin (2004) and Mo et al. (2004) alsostudied a s… 相似文献
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Based on the nonlinear model of two-dimensional random sea waves, a statistical distribution of wave surface slope exact to the third order is derived by using the expansion of the characteristic function and direct calculations of each order moment. Based on the distribution of wave surface slope derived in this paper, a whitecap coverage is proposed by using the limit surface slope as a criterion of wave breaking. The whitecap coverage expressed by the model depends on three parameters which can be determined in principle by the linear wave spectrum and three kinds of wave-wave interaction. 相似文献
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It is a good test for a numerical model to simulate progressive waves propagating over a submerged bar with a relatively high ratio of slopes. In this paper, the combined IB–VOF model is used to predict nonlinear dispersive waves propagating over a submerged bar with both slopes of 1:2. The predicted free surface elevations are compared with the experimental data and numerical results presented by other researchers. The comparison shows that the IB–VOF model is able to provide satisfactory wave profiles in the shallow water with strong nonlinear effects and in the wave transmitted region with strong wave dispersion in particular. Moreover, the wave evolution behind the submerged bar is described in detail, including the spatial wave profile modulation, spectral analysis of the time-series waves, flow velocity and pressure fields, and kinetic energy distribution. The effect of fluid viscosity on the numerical simulations is also studied, and it is found that the effect on the wave evolution considered in this paper is not significant. Finally, the hydrodynamic force acting on the bar is calculated using the IB–VOF model. 相似文献
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A class of E1 Niйo atmospheric physics oscillation model is considered. The E1 Niйo atmospheric physics oscillation is an abnormal phenomenon involved in the tropical Pacific ocean-atmosphere interactions. The conceptual oscillator model should consider the variations of both the eastern and western Pacific anomaly patterns. An E1 Niйo atmospheric physics model is proposed using a method for the variational iteration theory. Using the variational iteration method, the approximate expansions of the solution of corresponding problem are constructed. That is, firstly, introducing a set of functional and accounting their variationals, the Lagrange multiplicators are counted, and then the variational iteration is defined, finally, the approximate solution is obtained. From approximate expansions of the solution, the zonal sea surface temperature anomaly in the equatorial eastern Pacific and the thermocline depth anomaly of the sea-air oscillation for E1 Niйo atmospheric physics model can be analyzed. E1 Niйo is a very complicated natural phenomenon. Hence basic models need to be reduced for the sea-air oscillator and are solved. The variational iteration is a simple and valid approximate method. 相似文献
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８５—９０４—０８—０１和８５—９０４—０８—０２通过评审１９９５年１２月１２—１３日，受国家科委委托地矿部科技司组织专家鉴定组，在北京对“八五”国家科技攻关项目的“８５—９０４—０８一川和８５—９０４—０８—０２”专题进行了评审。卜述两专题经过５年... 相似文献
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In this paper, without recourse to the nonlinear dynamical equations of the waves, the nonlinear random waves are retrieved from the non-Gaussian characteristic of the sea surface elevation distribution. The question of coincidence of the nonlinear wave profile, spectrum and its distributions of maximum (or minimum) values of the sea surface elevation with results derived from some existing nonlinear theories is expounded under the narrow-band spectrum condition. Taking the shoaling sea wave as an example, the nonlinear random wave process and its spectrum in shallow water are retrieved from both the non-Gaussian characteristics of the sea surface elevation distribution in shallow water and the normal sea waves in deep water and compared with the values actually measured. Results show that they can coincide with the actually measured values quite well, thus, this can confirm that the method proposed in this paper is feasible. 相似文献